DEVASTATION: This was a familiar scene in and around New York City in the wake of Hurricane Sandy. Photo: Discovery Channel

Thousands of people are still dealing with the destruction wrought by Hurricane Sandy — and will be, for years to come.

The storm, which tore through the Eastern Seaboard nearly three weeks ago (Oct. 29 and 30), was unprecedented in its ferocity — surpassing even the dire predictions of scientists and weather experts. Over 120 were killed, including 43 people in New York City.

Tomorrow night, Discovery’s “Curiosity” series, in an episode entitled “Megastorm,” tries to explain the forces of nature which combined to make Hurricane Sandy the worst natural disaster to ever rock this area.

(It’s joined by two other Sandy-related specials airing tomorrow night: an episode of PBS’s “Nova” and History’s “Superstorm 2012.”)

With so many images of Sandy still fresh in our minds, I won’t rehash many of the harrowing clips featured tomorrow night in “Megastorm.” They’re no less horrific three weeks later.

What “Megastorm” succeeds in doing — in giving a detailed, chronological look at both the storm’s formation and its aftermath — is explaining the “whys” and “hows” of Sandy. Using high-tech computer graphics and actual (very frightening) satellite imagery of Sandy, it makes some sense of the storm, and lays the scientific groundwork for its subsequent devastation.

There are interviews with people from the National Weather Service and NOAA meteorologists, who describe, in layman’s terms, the unprecedented convergence of a jet stream mixed with arctic air — directed toward the Eastern Seaboard by unheard-of wind currents (and a full moon, which only exacerbated wave levels).

“We knew, right off the bat, that we’d be dealing with a monster of a storm,” says one weather expert. “There was a lot of disbelief . . . We thought, ‘There is now way this is going to happen.’ ”

There are also interviews with some of those effected by the storm, including a resident of Mantaloking, NJ; a firefighter who battled the Sandy-induced blaze that destroyed 111 homes in Breezy Point, Queens; residents of Staten Island, a chunk of which was destroyed (with water reaching a depth of 16 feet in some places); and a woman who went into labor at NYU/Langone Medical Center just as it lost power (she was rushed to Mount Sinai Hospital). Frightening.